1. Field of the Invention
The present invention relates to a dishwashing machine capable of carrying out a normal dishwashing program using a powder detergent as well as programs using solid detergents with additives having rinse aid properties and/or water softening properties.
2. Description of the Related Art
It is well known in the art of dishwashers the possibility of using, instead of powder detergent and liquid rinse aid, solid compositions called “2 in 1” compositions since they performs the function of the detergent and of the rinse aid which, in the traditional washing programs, has to be added in a specific “ad hoc” dispenser. There are also available on the market so called “3 in 1” solid compositions that, in addition to the above two functions (detergent+rinse aid), contain further additives having water softening purposes, therefore eliminating the need of using the water softening device and therefore the use of salt for ion exchange resins regeneration. Quite recently, the detergent producers have launched on the market “4 in 1” and “5 in 1” solid compositions or tablets, which have also other properties like a special care for stainless steel or silver and for glasses; for the purpose of the present invention “4 in 1” and “5 in 1” compositions are equivalent to “3 in 1” compositions.
The appliance producers had to adapt the range of dishwashers to the new family of detergents. Several approaches have been adopted, for instance by adding a “2 in 1” and “3 in 1” button to the user interface of the machine as disclosed by DE 10220839 A1 or by adding an “ad hoc” program to the machine, as disclosed by EP 1362547 A1, according to which the regeneration function of the water-softening device is switched off. These known solutions make the use of the dishwasher more cumbersome since the user does not usually like to have complex user interfaces with many buttons and/or a selection of too many washing programs. Moreover, there is always the possibility that the user load a “2 in 1” or “3 in 1” composition and then he/she forgets to adjust the button/program accordingly, therefore leading to a poor result of the washing program.